Method of providing perforations in acoustical tiles



Feb. 2, `1954 DALPHONE 2,667,925

METHOD OF PROVIDING PERFORATIONS IN ACOUSTICAL TILES Filed Dec. 23, 1948 JNVENToR, au15 .fa @one ffl/(gr.

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Patented Feb. 2, 1954 METHOD F PROVIDING PERFORATION S IN AOOUSTICAL TILES Louis J. Dalphone, Chicago, Ill., assignor to Certain-Teed Products Corporation, Chicago, Ill., a corporation of Maryland Application December 23, 1948, Serial No. 67,003

3 Claims.

This invention relates to an improved method of providing perforations in acoustical tiles, and particularly to the formation of such perforations in a tile formed of Fiberglas or' other mineral fibers. As is set forth in the co-pending application of Randolph P. Copeland, Serial No. 51,273, filed September 25, 1948, it is highly advantageous in connection with an acoustical tile that it be provided with a great number of small shallow openings in its face, with such openings formed by a punching operation in which the material of the tile is pushed forwardly ahead of the punch so as to provide a substantially compressed face portion of the tile material at the bottom of the perforation, and in which the withdrawal of the punch from the opening is effected without the removal of any of the tile material.

It is one of the objects of this invention to provide improved punching means by the use of which clean-cut, sharply defined openings may be formed conforming accurately to the shape of the punch, whereby the perforations formed by a plurality of similar punches may be similar to each other to a high degree in their appearance and in their effectiveness for bringing about the absorption of sound by the tile.

To this end, it is one of the objects of this invention to provide an improved method of punching in which the initial contact of the punch with the face of the tile is confined to a sharpened edge portion having an outline corresponding to the size vand shape of the punch, such effect being brought about preferably by the provision of a tapered depression in the end face of the punch whereby the required degree of sharpness of the cutting edge of the punch may be brought about for insuring the effective severing of the bers for providing at least directly on the face of the tile a clean-cut opening of the desired predetermined shape, while at the same time the tapered opening in the end face of the punch is so shaped as to prevent the yplug of tile material compressed ahead of the punch from becoming lodged in the tapered opening and thus to prevent such plug from being removed from the tile with the punch when the punch is withdrawn from the newly formed opening.

It is another object of this invention to improve the method of punching acoustical tiles in sundry details hereinafter pointed out. The preferred means by which the several objects have been attained are illustrated in the accompanylng drawing, in which:

Fig. 1 is a face View of a fragmentary portion of a tile made by my improved method.

Fig. 2 is a cross-sectional view vtaken substantially at the line 2-2 of Fig. 1.

Fig. 3 is an enlarged detail view partly in section, showing my improved punch in position at the end of a punching operation; and

Fig. 4 is a view similar to Fig. 3 but showing the conditions at the start of a punching operation.

Referring now to the several figures of the drawing, in which corresponding parts are indicated by the same reference characters, I0 indicates an acoustical tile made of mineral fibers and preferably in the form of a Fiberglas panel three-fourths of an inch in thickness and of such size and shape as to be handled conveniently for installation and as to present the desired attractive appearance in accordance with a predetermined pattern.

As is shown in Fig. 1, the panel or tile lll isl provided in its display face with a plurality of perforations or openings vIl extending into the body of the tile, such openings l I being preferably of comparatively small size and shallow depth.

In the arrangement illustrated, the openings Il are circular in form, of a diameter of about five thirty-seconds of an inchy and of a depth of about a quarter of an inch. The openings as shown are arranged in rows and cross rows, on about half inch centers'in both directions.

In the operation ofproviding perforations in the faces of acoustical tiles as above specified for use on a wall, it is highly important that very great care be exercised in the formation of the perforations for insuring that the fibers directly at the face of the tile be severed accurately at the line of the pattern of the perforation so as to make the opening conform in size and shape with the predetermined design. This is of importance in view of the fact that even slight irregularities in the size or shape of the perforations, or slight departures from regularity in the face portions of the tile adjacent to the perforations, are likely to be detected readily by even a casual observerv by reasonof variations in the light and shade effects.

I have found that the operation of forming the perforations in the face of a Fiberglas tile can be effected to very great advantage and with highly desirable results in the matter of producing a clean-cut sharply defined opening by the use of a solid punch hollowed out at its operative end so as to present a sharpened edge to the bers of the tile. By the use of such a punch having a sharpopening fshallconform to the predetermined desired shape. The action of the punch upon the application of pressure upon the Fiberglas fibers tion, but conditions are such as to enable the punch at the point of initialpressure-contact to4` provide a smooth sharplyvdened perforation: Upon continued movement of the punch into the through the sharpened cutting edge ofthe punch. is more or less of a breaking' or'shearing;opera-V body of the tile after the initiialfAseveringwof*the Y fibers at the face of the tile, the cut-out material is pushed ahead of the punch so as to befcomJ-v' pressed, the pressure directly on the bers to be severed; after 'such-initial' severing of the-fibersv at the face of the tileybeingqapplied .moreand more thro'ughthe mediumof fth'e fcompressed body material rather than by th Vpunch itself. application of pressure throughV the' medium of theicompressed'material,1the'tendency for the production of alsharply'deiinedopening conforming-'to.=thesh`ape of' the VVpunch is very greatly lessened'or'entirelyieliminated, but this is Yof no great importance so long as the outer end portion of th'ebpeningfis :clean-cut and sharplydefined.

For accomplishingthedesired 'results as above set' forthg'i I lprefer: to iemploy a round ypunch l2 h'avin'g-` its'op'erativeenclfaceiliolloWedA out by the provisionirof a'conical recess; il 3 .therein produced' prefrablyl by' a boring operation. In this Way,

the vpunchlisprovided with fa sharpened v'cutting edgeoflcircular'fform" corresponding' to the size and shape of the punch and to thesize and shape of thehole-Sto be formed. With such cutting edge brought into engagement initially Iwith the fibers of thevtileas-shown in Fig;V 4; the'rbers directly at the face lof 'the tileiare*severedv 'accurately at thelline ofv the patternofthe opening'whereby the punchvproducesfaesharply defined circular opening; atlleastatfthe outerlendportion of 'the opening; Asv thel material lbecomes'r compressed ahead 'of the punch Voni-the `continued movement of" th'e p'unclfintd thebodyrof the tile,l further pressure is vapplied onf-.the bers 'through f such compressed materialinstead of vdirectly by and through "the cuttingfedgelwith. the result "that the side face-portions ofthe perforation's maybe com; parati-velyuneven and rough in'contrast with' the smooth and'regularl formation-of '.theimouthpontion's'ofithelopeningsr:y The consistency' of .the tile materi'al issuch,1 however-,that theV regularity of' 'the :mouth 4porti'or1f`fof fthe-"opening is notH disturbed or changedS-.bythelpossible production of comparatively rougher face portionsf at points beyond the mouths 'of the openings. y

In carrying out my `improved process or method', I *prefer to emplyl a lplurality ofi thelv improved punches l2"arrangedflin` the formof aV battery adapted 'to be operated-inunisonforthe produc- In this' tion of a great number of the openings Il by a single operation, but my invention is not to be limited to such a procedure. I have found that a battery of four or five hundred of such punches can be pressed perpendicularly into the face of a Fiberglas tile of the type above described so as to produce: the desired-@number of perforations without: great l difficulty,' With'fthe perforations highly effective for causing the absorption of sound, and with the outer end portions of the perorations formed accurately and true to the circularildesign sought.

I'claim:

1. The 'method .off providing perforations in the facenofianacoustical tile, comprising applying pressure to :the face of the tile principally upon a sharply denedroutline corresponding to the pattern of the opening to be formed so as to effectiniti'al severing of the tile material along such outline, then pressing the severed material into the body 'offthetilevfor effecting further severing ofzthe-tilexmaterial andfserving to extend the opening-inW-ardlyfand' to compress the material atthebottom ofthe'opening., and then Withdrawingffrom the-tile the-means for applying pressure so as torleaveithe Vcompressed tile material in poV sition at the bottomvofthe opening;

2. The-methodvof -providing perforationsin anY acoustical tile` comprising the step of severing the material`v of :the tile by v'means of a -hollow ended round Ypunch withtheinitial pressureof the punch onthezface of :theftile confined to acircular outline' corresponding to `the `size of the perfora'tionto-` be made, thenLaDplying pressure on the :tile materialinside-'of said circular outline for compressingsuch material Vandpressing it forwardly ahead ofthe Ypunch into the body of the tile to the predetermined selected depth, and then withdrawing the punchso `as toy leave the compressed material Y in position Awith Aacompressed face-portion at thebottom of theperforation.

3. The methodof providing perforationsin an acoustical.tilefcomprisingfthe step of pressing a punch' into the tilef'vvith `the initial pressure connedfto a sharpened edgefportioncorresponding to' the-size= and:A shapey of the punch rand serving as the punch advances to severthe tile material ahead of the punch-fromthe adjacenttile material, then faf ter f thefinitial :application of pressure `forcingthematerialof thetile inside of said outline forwardlyfahead--of the punch; and then withdrawing-*the punch so 'as to leave aA cornpressedvfacey portion' off` the tile- -material at the Lucius Aug. 8, 1944 ...afb-...1 

